Implantable medical devices have been used effectively to treat many medical conditions and disorders. For example, implantable stimulators can be used in neurological therapy by stimulating nerves or muscles, for example, stimulating the spinal cord or other nerves for treatment of pain; for urinary urge incontinence by stimulating nerve fibers proximal to the pudendal nerves of the pelvic floor; for erectile and other sexual dysfunctions by stimulating the cavernous nerve(s); for reduction of pressure sores or venous stasis; etc.
Implantable stimulators typically include a housing that contains the electronic circuitry and a power source that produces electrical pulses at exposed electrodes, which may be connected to the housing via a lead, for stimulation of the tissue. It is preferable that the electronic circuitry and power source be held within the housing in a hermetically-sealed environment for the protection of the user and the protection of the circuitry and power source. It can be convenient or economical to form the housing and other portions of the exterior of the stimulator (or other medical device) out of plastic materials. Interfaces between these materials must be sealed to form the hermetic environment within the housing. Sealing a polymer-polymer interface can be time-consuming and many methods for sealing may include or produce materials that are potentially not biocompatible or may require a regulatory approval process to permit their use in sealing the housing.